Ankle–brachial index and brachial–ankle pulse wave velocity as markers of severe aortic regurgitation: a hospital-based cohort study

Severe aortic regurgitation (AR) causes characteristic peripheral hemodynamic changes. This study aimed to evaluate the association between vascular parameters and AR severity and determine whether ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) reflect these changes and can serve as markers for identifying severe AR. We retrospectively analyzed 6769 patients undergoing echocardiography and vascular function testing, excluding patients with peripheral artery disease, dialysis, atrial fibrillation, or moderate or severe non-AR valvular disease. Participants were stratified by AR grade (0-4). Associations were examined using multivariable logistic regression. Receiver operating characteristic (ROC) curve analysis was performed for ABI and baPWV, and an optimal cutoff-based four-group classification was constructed. ABI remained stable across AR grades 0-3 and sharply increased in AR 4 (median 1.35), whereas baPWV was lowest in AR 4 (1307 cm/s). ABI (per 0.01 increase; odds ratio [OR] 1.16, 95% confidence interval [CI] 1.13-1.18) and baPWV (per 100 cm/s increase; OR 0.80, 95% CI 0.74-0.86) were independently associated with AR 4. Area under the curve was 0.88 and 0.75 for ABI and baPWV, increasing to 0.90 in the combined model. In a combined model using ROC-derived cutoffs (ABI ≥ 1.26 and baPWV <1330 cm/s), the high-ABI/low-baPWV group showed independently increased odds of AR 4 after adjustment for age, sex, and brachial pulse pressure (OR 49.71, 95% CI 22.15-88.54). Elevated ABI and reduced baPWV served as complementary markers of severe AR, and their combined assessment may facilitate early identification and prompt referral for echocardiographic evaluation.